vintage Pairpoint silver plate shaker, sugar caster or pounce pot sander?

Vintage Pairpoint quadruple plate silver shaker with nearly all of the silver worn away from polishing and use. We love it just as it is, with its flowery repousse design.

We're inclined to believe this is a muffineer / sugar shaker, rather than a sander (it seems a little late to be a sanding pot). It's about 4 1/2" tall.